Amtrak said in a news release that the area to be developed incorporates 14.07 acres, which includes 613,075 square feet of land and 1,328,804 total square feet of building area.

The tract also includes 1,679 parking spaces and 3 million total buildable square feet of excess air-rights.

Working with Amtrak on the project are the City of Chicago, Metra commuter rail and the Regional Transportation Authority, and consulting firm KPMG.

“We are excited to be a step closer to securing a master developer to assist us in realizing the full potential of Chicago Union Station and our other Chicago properties,” said Bart Bush, Amtrak vice president, asset and real estate development, in a statement.

Eleven months ago, Amtrak sought local, regional and national developers interested in the opportunity to redevelop the station and adjacent land as well as improvements to passenger and employee facilities.